Prevent exception when choosing culture for generated county holder (#…

…1539)

ImperatorToCK3/CK3/World.cs

@@ -680,16 +680,45 @@ private void GenerateFillerHoldersForUnownedLands(CultureCollection cultures, Co
 				}
 			}
 
-			Province province;
+			var candidateProvinces = new OrderedSet<Province>();
 			if (county.CapitalBaronyProvince is not null) {
-				province = Provinces[county.CapitalBaronyProvince.Value];
-			} else {
-				province = county.CountyProvinces
-					.Select(p => Provinces[p])
-					.First(p => p.GetFaithId(date) is not null && p.GetCultureId(date) is not null);
+				// Give priority to capital province.
+				candidateProvinces.Add(Provinces[county.CapitalBaronyProvince.Value]);
 			}
-			var culture = cultures[province.GetCultureId(date)!];
-
+			var allCountyProvinces = county.CountyProvinces
+				.Select(p => Provinces[p]);
+			candidateProvinces.UnionWith(allCountyProvinces);
+			var province = candidateProvinces
+				.First(p => p.GetFaithId(date) is not null);
+
+			var culture = candidateProvinces
+				.Select(p => p.GetCulture(date, cultures))
+				.FirstOrDefault(c => c is not null);
+			if (culture is null) {
+				Logger.Debug($"Trying to use de jure duchy for culture of holder for {county.Id}...");
+				var deJureDuchy = county.DeJureLiege;
+				if (deJureDuchy is not null) {
+					culture = Provinces
+						.Where(p => deJureDuchy.DuchyContainsProvince(p.Id))
+						.Select(p => p.GetCulture(date, cultures))
+						.FirstOrDefault(c => c is not null);
+				}
+				if (culture is null && deJureDuchy?.DeJureLiege is not null) {
+					Logger.Debug($"Trying to use de jure kingdom for culture of holder for {county.Id}...");
+					var deJureKingdom = deJureDuchy.DeJureLiege;
+					culture = Provinces
+						.Where(p => deJureKingdom.KingdomContainsProvince(p.Id))
+						.Select(p => p.GetCulture(date, cultures))
+						.FirstOrDefault(c => c is not null);
+				}
+
+				if (culture is null) {
+					Logger.Warn($"Found no fitting culture for generated holder of {county.Id}, " +
+					            $"using first culture from database!");
+					culture = cultures.First();
+				}
+			}
+
 			bool female = false;
 			string name;
 			var maleNames = culture.MaleNames.ToImmutableList();